[sonic-py-common] Add interface utilities (sonic-net#5113)

* Add sonic_interface.py in sonic-py-common for sonic interface utilities to keep this SONIC PREFIX naming convention in one place in py-common and all modules/applications use the functions defined here.

src/sonic-config-engine/minigraph.py

@@ -15,6 +15,7 @@
 
 from portconfig import get_port_config
 from sonic_py_common.multi_asic import get_asic_id_from_name
+from sonic_py_common.interface import backplane_prefix
 
 """minigraph.py
 version_added: "1.9"
@@ -37,7 +38,6 @@
 
 FRONTEND_ASIC_SUB_ROLE = 'FrontEnd'
 BACKEND_ASIC_SUB_ROLE = 'BackEnd'
-BACKEND_ASIC_INTERFACE_NAME_PREFIX = 'Ethernet-BP'
 
 # Default Virtual Network Index (VNI) 
 vni_default = 8000
@@ -729,7 +729,7 @@ def filter_acl_table_bindings(acls, neighbors, port_channels, sub_role):
     # architecture
     for port_channel_intf in port_channels:
         backend_port_channel = any(lag_member in port_alias_asic_map \
-                                   and lag_member.startswith(BACKEND_ASIC_INTERFACE_NAME_PREFIX) \
+                                   and lag_member.startswith(backplane_prefix()) \
                                    for lag_member in port_channels[port_channel_intf]['members'])
         if not backend_port_channel:
             front_port_channel_intf.append(port_channel_intf)
@@ -751,7 +751,7 @@ def filter_acl_table_bindings(acls, neighbors, port_channels, sub_role):
         # This will be applicable in Multi-NPU Platforms.
         front_panel_ports = []
         for port in group_params.get('ports', []):
-            if port in port_alias_asic_map and port.startswith(BACKEND_ASIC_INTERFACE_NAME_PREFIX):
+            if port in port_alias_asic_map and port.startswith(backplane_prefix()):
                 continue
             if port in port_channels and port not in front_port_channel_intf:
                 continue

src/sonic-py-common/sonic_py_common/interface.py

@@ -0,0 +1,43 @@
+"""
+ Dictionary of SONIC interface name prefixes. Each entry in the format
+ "Human readable interface string":"Sonic interface prefix"
+ Currently this is a static mapping, but in future could be stored as metadata in DB.
+"""
+
+SONIC_INTERFACE_PREFIXES = {
+    "Ethernet-FrontPanel": "Ethernet",
+    "PortChannel": "PortChannel",
+    "Vlan": "Vlan",
+    "Loopback": "Loopback",
+    "Ethernet-Backplane": "Ethernet-BP"
+}
+
+def front_panel_prefix():
+    """
+    Retrieves the SONIC front panel interface name prefix.
+    """
+    return SONIC_INTERFACE_PREFIXES["Ethernet-FrontPanel"]
+
+def backplane_prefix():
+    """
+    Retrieves the SONIC backplane interface name prefix.
+    """
+    return SONIC_INTERFACE_PREFIXES["Ethernet-Backplane"]
+
+def portchannel_prefix():
+    """
+    Retrieves the SONIC PortChannel interface name prefix.
+    """
+    return SONIC_INTERFACE_PREFIXES["PortChannel"]
+
+def vlan_prefix():
+    """
+    Retrieves the SONIC Vlan interface name prefix.
+    """
+    return SONIC_INTERFACE_PREFIXES["Vlan"]
+
+def loopback_prefix():
+    """
+    Retrieves the SONIC Loopback interface name prefix.
+    """
+    return SONIC_INTERFACE_PREFIXES["Loopback"]